The present invention relates to a new and improved construction of apparatus for clamping and unclamping a warp beam in a beam warping machine.
Generally speaking, the chucking and dechucking apparatus of this development is of the type comprising a centering and entrainment device which is arranged at the inner end of two stub shafts mounted to be axially displacable in side plates of the beam warping machine.
Equipment of this type which is used at beam warping machines are generally known to the art. The warp beam is provided at its ends with stub shafts or recesses, advantageously conical recesses, with which coact the correspondingly constructed ends of the centering and entrainment device in one axially displaced position, in order to remove an empty warp beam which has been raised by the lifting-in and lifting-out device from the latter, for centering such empty beam and coupling the same with a rotary drive. The centering and entrainment device is brought into the other axially displaced position, so that the wound warp beam can be lifted-out and replaced by an empty warp beam. During the warping operation a press or contact roll is pressed against the outer surface or jacket of the warp beam or the warp threads which have been wound thereon, as the case may be, this contact or press roll ensuring for a uniform density of the package of warp threads which have been wound onto the warp beam.
This press roll must be arranged exactly parallel to the axis of the warp beam and between its beam discs. This requires considerable accuracy in the positioning of the clamped or chucked warp beam.
From German Patent Publication No. 1,535,168 there is known to the art an apparatus of the previously mentioned type, wherein the warp beam provided with journals at its ends is supported and entrained by means of such journals by stub shafts which are mounted to be rotatable and axially displacable in the machine frame. The mounting arrangement is accomplished by means of special bearings containing internally threaded sleeves or bushings which are threaded on to externally threaded bushings or sleeves. By rotating the internally threaded bushing, connected with a stub shaft, upon the externally threaded bushing, connected with the machine frame, it is possible to axially shift the stub shaft. The stub shafts supporting the warp beam are thus connected with separate devices for performing axial displacements in order to release and advance the centering and entrainment device as well as for positioning the chucked or clamped warp beam. These separate devices must be activated individually by hand or by means of motors through the air of special drive elements, in order to be able to chuck or release the warp beam. For the lateral adjustment of the warp beam, both of the displacement devices can be coupled with one another and can be conjointly actuated by a manual or mechanically driven drive device. This requirement that the clamping devices at both sides of the warp beam be separately actuated is time-consuming, and furthermore, associated with the danger that the contact or press roll will not be introduced between both of the warp-beam discs, something which can lead to appreciable damage of the equipment.
Similar, likewise purely mechanical devices for clamping or unclamping a warp beam have also been disclosed in German Pat. No. 1,102,660 and German Utility Model No. 7,312,497. Also, in this case, threaded bushings or sleeves are used for the axial displacement in order to advance the centering and entrainment device.
In order to preclude the danger that the position of the warp beam will be improperly estimated and to reduce the set-up time, it has been proposed according to German Patent Publication No. 2,450,757, where there has been disclosed an apparatus of the previously mentioned species, to axially displace with a motor drive the centering and entrainment devices at both sides of the warp beam and to provide an electrical control device which coacts with measuring devices for determining the position of the warp beam. This control device is capable of automatically delivering control signals for the activation of the adjustment drives of the bearing shafts. The adjustment drives are constructed as piston-and-cylinder drives, wherein, in each case, the piston rod of a cylinder forms the axially displacable bearing shaft for the warp beam. Also, this prior art reference teaches the use of separate displacement devices to both sides of the warp beam, and in particular there is disclosed an arrangement whose construction is quite complicated in order to ensure for a proper positioning and chucking of a warp beam.
The immediately discussed prior art equipment has been improved upon with a construction as disclosed in the German Patent Publication No. 2,628,788 wherein there is used in lieu of one of both piston-and-cylinder drives, an electric motor which is coupled by means of its bearing shaft, through the agency of an adjustment securing device which is effective in rest condition, especially by means of a screw drive, with a self-locking worm. Additionally, the displacement of the bearing shaft which is hydraulically displacably mounted in the side plate, here is accomplished differently than with the device disclosed in the previously mentioned German Pat. No. 2,450,757, and specifically, such displacement is undertaken by means of a lever arranged externally of the related side plate. This lever is pivotably mounted at its one end by means of a support at the side plate and at its other end is connected with the piston rod of the piston-and-cylinder drive and at which there is hingedly connected approximately at its center the bearing shaft.
The equipment of this prior art reference therefore again contains two separate advance or feed devices requiring a correspondingly great constructional expenditure.
The previously discussed prior art apparatuses, apart from the drawback of considerable constructional expenditure required for the displacement devices which are separately provided at each side of the warp beam, have common to them the further disadvantage that the feed or advance of the centering and entrainment devices towards the warp beam can hardly be accomplished in synchronism because of the separate displacement devices. As a result, as a rule the warp beam must be chucked while shifted out of the correct center position towards the side of the least resistance, and only thereafter the installation must be further adjusted.